The nation's retailers lost steam in April, missing views Thursday as shoppers took a break from an early Easter binge. But chains enjoyed a healthy spring season overall, prompting many outfits to raise profit forecasts and suggesting that the retail recovery continues to accelerate. April sales of stores open at least a year rose just 0.8% vs. a year earlier, says Ken Perkins, president of Retail Metrics. That fell well short of Wall Street's